A lot of pallets are hardwood and (IMO) be difficult to work with. Pallets would be best used as hive stands, or if tough condition ... campfire wood. :)They'd have to be 'some serious' top end pallets before I'd consider trying to salvage the wood.

I've seen people use old fencing to make top bar hives and nucs. A guy on youtube has a few videos showing his hives and nucs made out of them. OutOfaBlueSky is his user name if you want to check some of them out.

I heard that if you can find an old chestnut fence (pre chinese chestnut blight) and resaw the wood is fabulous. I believe some arborist imported the blight and it wiped out the American chestnut, on which the north eastern lumber industry was built. Also heard that American chestnut was more decay resistant than cedar ... so if I could find THAT fence I'd do it too! :-D